1. Field of the Invention
The present invention relates to a voice recording and/or reproducing device.
2. Description of the Related Art
Recently, a device, which is a so-called digital voice recording and/or reproducing device (hereinafter called simply "digital voice recorder"), for recording and/or reproducing a voice has been developed.
The digital recorder collects a voice as an analog signal by a microphone or the like. The analog signal representing the collected voice is converted to a digital signal which is then stored in a storage medium (for example, an IC memory) of the digital recorder. When the recorded voice is reproduced, the stored digital voice is read out from the storage medium and converted to an analog signal. The analog signal is then reproduced by a speaker or the like.
When the digital signal is stored in the storage medium, the digital recorder generally applies a coding technique to compress the volume of data efficiently for saving the space of the storage medium.
The lower the bit rate for coding becomes, the more the volume of the stored digital signal is compressed so that the voice can be recorded for a long time. However, when the bit rate for coding becomes lower, the quality of the reproduced voice deteriorates in proportion to the decline of the bit rate.
Reversely, when the bit rate for coding becomes higher, the quality of the reproduced voice improves in proportion to the increase of the bit rate. However, the data compression rate declines so that the voice cannot be recorded for a long time.
Japanese Laid-Open Patent Application Publication No. Hei 2-94200 discloses a method for recording a voice that switches, if necessary, a coding means between a high quality recording mode for reproducing the recorded voice in high quality and a long time recording mode for recording the voice for a long time.
However, if the recording modes are changed over during the voice recording, the device will reproduce at the change over point a reproduced voice that sounds substantially differently than the input voice and that may be uneasy to listen.